I would contact your local NRA rep. He/she will at least be able to direct you to an attorney who enjoys firearms and has experience setting up an NFA trust.
I would make sure to get a local lawyer. Many of those deals you see where a law firm will set up an NFA trust anywhere for $500 are not legal trusts in your given state.
Obummer wrote an executive order limiting the power of NFA trusts. I would find out the details of the executive order before I spent a lot of money setting up a trust.